Bell nonlocality – quantum correlations from principles

Ana Belen Sainz (Perimeter Institute)

In this tutorial I will discuss correlations in Bell scenarios and the problem of characterising them from basic principles. I will begin by presenting Bell’s theorem from the modern perspective of causal models, and show how quantum theory exhibits nonclassical correlations. I will further introduce the concept of Bell inequalities and of correlations beyond quantum theory. I will then move on to the question of how to characterise from basic postulates the correlations featured by quantum theory. I will discuss a selection of principles, such as Nontrivial Communication Complexity and Macroscopic Locality, and finally introduce the barrier that we currently face: almost quantum correlations.